In the field of magnetic recording and/or reproducing apparatus, such as an audio tape recorder or a video tape recorder (VTR), for example, the general tendency is towards a higher recording density and a higher quality of recording signals. In keeping with this tendency towards the higher recording density, a so-called metal tape in which powders of metals such as Fe, Co or Ni, or alloys thereof, are used as the magnetic powders, or a so-called vacuum-deposited tape in which a magnetic metal material is directly deposited on a base film by the thin film forming vacuum technique, has been developed and put to practical use in many technical fields.